The smell of the shampoo and fragrance of the soaps we use for personal cleansing are a source of relaxation and comfort, whether it be first thing in the morning to help us wake up or for a hot bath to unwind after a hard day. Many new soaps and shampoos are now incorporating aromatherapy essential oils and herbal remedies to assist in relieving stress and providing other health benefits.
No doubt the Personal Care industry is interested in depositing sensorial and/or beneficial ingredients on skin and hair from surfactant containing formulations. Often these ingredients are hydrophobic oils such as fragrances. There is a need for (deposition) systems that in themselves are safe, readily available, renewable, biodegradable, natural or at least lightly modified with chemicals. Modified starches of this invention fill this need. Surprisingly, starch stabilized emulsions prepared according to this invention can stabilize oil-in-water emulsions of the oily ingredients, remain intact in the presence of surfactant solutions and adhere the ingredient to hair or skin.
It would be ideal if those beneficial smells and fragrances were to remain on the skin/hair for a period of time longer so that their aromas could be enjoyed long after one steps out of the shower.
One of skill in the art would realize that if enough of the fragrance oil is added to the shampoo or soap some small percentage of the material will be trapped or absorbed on the surface and provide an extended release of the aroma. This method of achieving long lasting smells is obviously not cost effective as a very high percentage of the fragrance is lost down the drain. In the meantime the surfactants are utilized in the shampoo or soap to remove oily material from the hair (sebum) and skin which are in many respects similar to the fragrances which are ideally left on the substrate.
The manufacturers of these shampoos and soaps would like to use as little of the fragrance oil as possible to be cost effective. Typically these essential oils are formulated at less than one percent in the final shampoo and in some cases significantly less than that. So there is still a huge need in the market place for an effective delivery system for fragrant oils and the like from high surfactant systems such as shampoos and body soaps.